LA-ICPMS for In Situ U-Th Dating of Holocene Stalagmites.

ABSTRACT: Here, we present an in situ U-Th dating approach of carbonate speleothems using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) with a detection efficiency of 1-2%. By online addition of a ²²⁹Th-²³³U-²³⁶U isotope triple spike to the laser-generated aerosol, instrumental mass discrimination and U/Th elemental fractionation could be monitored and corrected. With this approach, the ²³⁴U/²³⁸U and ²³⁰Th/²³⁸U activity ratios of a flowstone sample in secular equilibrium could be accurately reproduced as unity with two-sigma uncertainties ±0.053 and ±0.050, respectively. The method was used for the determination of the formation ages of individual layers in natural stalagmites ranging between

SUBMITTER: Wu CC 

PROVIDER: S-EPMC11307247 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature